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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16761 results found.

  1. Polarimetry of GRB020813: evidence for variability
  2. GRB020812: optical observations
  3. GRB020813: High-Resolution Optical Observations
  4. GRB020813: Early Time Magnitude
  5. GRB020812: optical observations
  6. GRB020813, optical observations
  7. GRB020813, astrometric position
  8. GRB 020812 optical observation
  9. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  10. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  11. HST Imaging of the Host of GRB 011121
  12. GRB020801, optical afterglow candidate
  13. Further refinement to IPN error box for GRB020531
  14. GRB020331: Late-time Optical Light Curve (re-submission)
  15. GRB020331: Late-time Optical Light Curve
  16. GRB 020410: Discovery of Probable OT by HST
  17. IPN triangulation of GRB020708
  18. GRB 020705: Optical observations
  19. GRB 020625, optical observations
  20. GRB 020625: Optical observations
  21. GRB 020531: optical photometry of Chandra sources
  22. GRB020625 (=H2081): A Long Burst Localized by HETE
  23. The Probable Host Galaxy of GRB/XRF 020427
  24. GRB/XRF 020427, detection of an underlying system with the VLT
  25. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  26. AXP 1E2259+586 optical observations
  27. Fading Optical Source in the Field of GRB020531
  28. GRB 020531, INT+WFC deep optical upper limits
  29. GRB020405: polarimetric observations
  30. GRB 020531, simultaneous optical observations
  31. GRB 020604, optical observations
  32. GRB020531: Second epoch Chandra observations
  33. GRB020604, optical observations
  34. GRB020604, BVRcIc field photometry
  35. GRB020603, BVRcIc field observations
  36. GRB020531, BVRcIc field photometry
  37. GRB020531 Optical Observations
  38. GRB020531: Observations with the Chandra X-ray Observatory
  39. GRB020531, optical observations
  40. GRB020531(=H2042): Optical Observations
  41. GRB020531(=H2042): Optical Observations
  42. GRB020525, optical observations
  43. GRB020405 field photometry at ESO
  44. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  45. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  46. XRF 020427
  47. GRB 020124: Optical observations
  48. GRB020405: VLT observations of the OT environment
  49. GRB 020409: No Evidence for an Optical Afterglow
  50. GRB 020331 Kyoto observation on March 31
  51. X-ray afterglow of GRB020321
  52. BeppoSAX GRB : GRB020409
  53. GRB020331 optical observations with RIMOTS
  54. GRB020124 optical observations with RIBOTS/RIMOTS
  55. GRB020406(?), optical observations
  56. GRB020405, Radio Observations
  57. GRB 020405, U-band observations
  58. GRB020331 NIR observation at KPNO (re-submission)
  59. GRB02033 NIR observation at KPNO
  60. GRB020331 field photometry
  61. GRB 020331, NIR observations
  62. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  63. GRB 020322: BeppoSAX observations of the X-ray afterglow
  64. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  65. Near-Infrared Observations of GRB020322 at TIRGO
  66. GRB 020322: Optical Observations
  67. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  68. GRB 020321: Optical observations
  69. GRB020317 BVRI field photometry
  70. GRB011211 revised BVRI field photometry
  71. GRB020305 BVRI field photometry
  72. GRB020322 BVRI field photometry
  73. GRB020322: Candidate Optical Afterglow
  74. GRB 020322: Optical Sources and Improved Astrometry
  75. GRB020317: optical observations
  76. GRB020321 optical observations
  77. GRB020321: a faint BeppoSAX detection
  78. GRB 020317 : KISO Optical Observations
  79. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  80. GRB 020305: Optical Observations
  81. GRB020317, optical observations
  82. GRB 020317: Optical observations
  83. GRB020305: Properties of the Candidate Optical Afterglow
  84. GRB011130 (XRF011130) Second Epoch Chandra Observations
  85. GRB 020305: Optical observations
  86. XRF/GRB 011030: Detection of the Probable Host Galaxy
  87. GRB 020305: Candidate optical afterglow
  88. GRB020305, optical observations
  89. HST Imaging of the afterglow and host of GRB 011121
  90. GRB 010921: HST Observations
  91. SGR1900+14 activity
  92. GRB020124 BVRI field photometry
  93. GRB020127 Optical Observations
  94. SN2002ap (SN/GRB?) UBVRI Field Photometry
  95. GRB020127: Chandra Observations and Prospective Counterparts
  96. pre-SN2002ap (SN/GRB?) imaging of M74
  97. GRB020124, optical observations
  98. GRB 020127, I-band observations starting 3.14-hr after the event
  99. GRB010921 Optical Observations
  100. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE

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